Get my channel

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already establish readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description still adds real behavioral value by revealing that this targets the authenticated connected channel and returns precise (non-rounded) figures, i.e. private/authoritative data rather than public aggregate data.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no filler, and the payload contents are front-loaded before the sibling comparison. Every clause carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description compensates by listing the returned fields explicitly, and it covers the key differentiator from the nearest sibling. For a simple single-parameter read tool, nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single 'account' parameter is fully documented there, including the failure behaviour when multiple channels are connected. The description adds nothing about the parameter, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific resource (the connected channel) and enumerates exactly what is returned: subscribers, total views, video count and uploads playlist id. It also explicitly distinguishes itself from a sibling, get_channel, so an agent can separate the two without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The contrast with get_channel ('reads the exact subscriber count rather than YouTube's rounded public figure') gives a clear selection criterion between the two channel-reading tools. It stops short of stating broader when-to-use/when-not conditions, but the discriminating context is present.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.